Benchmark your PVE

There is a nice tool name prveperf, which, to say it simple, is a Proxmox benchmark.

It's output tell us:

CPU BOGOMIPS: bogomips sum of all CPUs

REGEX/SECOND: regular expressions per second (perl performance test), should be above 300000

HD SIZE: harddisk (root partition) size

BUFFERED READS: simple HD read test. Modern HDs should reach at least 40 MB/sec, modern SATA can do over 100 MB/sec.

AVERAGE SEEK TIME: tests average seek time. Fast SCSI HDs reach values < 8 milliseconds. Common IDE/SATA disks get values from 15 to 20 ms. FSYNCS/SECOND: value should be greater than 200 (you should enable 'write back' cache mode on you RAID controller - needs a battery backed cache (BBWC)).

DNS EXT: average time to resolve an external DNS name

DNS INT: average time to resolve a local DNS name (basically it resolves your local domain name)